CEC - Project Summary/Abstract Columbia's Superfund Research Program investigates the health effects, geochemistry, and remediation of arsenic (As), with a particular focus on groundwater. Its interdisciplinary teams of researchers work with government scientists to translate new findings into effective policies that reduce environmental exposures and improve human health. The Community Engagement Core serves to develop tools, resources, and strategies to build the capacity of individuals, communities, and government partners to reduce exposure to As through private well water. Our community of interest includes residents of Maine, New Jersey, and Minnesota who drink private well water in As-affected areas. Through partnerships with state government partners we will test intervention strategies centered on empowering individual well owners to take the actions necessary to ensure their safe quality drinking water. The specific protective actions that we will promote and facilitate are testing well water to identify As and other toxic hazards, treating or avoiding well water to reduce exposure to these hazards, and finally maintaining treatment systems and monitoring treated water to ensure continued quality. Mailed surveys to random addresses have been our primary strategy for engaging this diffuse community of private well users; through the participation of over 2000 households in As-affected communities in Maine and New Jersey we have developed new understanding about the psychological, situational, and socioeconomic factors that influence As testing and treatment behavior, as well as the information and assistance needs of private well users. We will assist government and community partners to design and evaluate small-scale interventions to target both psychological (behavioral) and situational barriers to well testing, utilizing targeted and tailored messaging, delivered through traditional and innovative channels. We aim to evaluate which are most efficient, effective (participation rate, wells tested, first-time tests), and/or most sustainable with regards to potential for scale-up within each state. We will continue to motivate and assist protective mitigation behavior among households who have tested and have found unsafe levels of As. Concerns and challenges faced by households in mitigating As exposure will be solicited through semi-structured interviews and focus group discussions to inform development of guidance materials for distribution with As test results. This process will also allow recruitment of private well owners who can act as community ambassadors to assist their neighbors overcoming similar challenges. Finally, we aim to evaluate and interpret lessons from the above activities so as to be relevant for various stakeholders and to inform policy ? assembling ?tool-kits? for reducing the cumulative impacts of As exposure. In collaboration with RTC, this portfolio of lessons learned ? encompassing effective messaging, community engagement strategies, and policy recommendations ? will be shared with current and future partners to build capacity at the community, local, and state levels to support private well owners through all stages of As exposure reduction.